Enhanced Molecular Networking Shows Microbacterium sp. V1 as a Factory of Antioxidant Proline-Rich Peptides

• Published in: Marine drugs Vol. 21; no. 4; p. 256
• Main Authors: Vitale, Giovanni Andrea, Scarpato, Silvia, Mangoni, Alfonso, D'Auria, Maria Valeria, Della Sala, Gerardo, de Pascale, Donatella
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 21-04-2023; MDPI
• Subjects: Animals; antioxidant; Antioxidant properties; Antioxidants; Bacteria; Carbon dioxide; Chromatography; Genomes; Laboratories; Low temperature; marine bacteria; Marine invertebrates; Metabolism; Metabolites; Microbacterium; molecular networking; Molecular Structure; Natural products; Networking; NMR; Nuclear magnetic resonance; Nuclear Magnetic Resonance, Biomolecular; OSMAC; Peptides; Peptides, Cyclic - chemistry; Planar structures; Proline; proline-rich peptides; Proteolysis; Stereochemistry; structure elucidation; Tandem Mass Spectrometry; Two dimensional analysis; bioactive peptides; antioxidant; molecular networking; marine bacteria; OSMAC; structure elucidation; proline-rich peptides
• ISSN: 1660-3397; 1660-3397
• DOI: 10.3390/md21040256

Two linear proline-rich peptides (
-
), bearing an N-terminal pyroglutamate, were isolated from the marine bacterium
sp. V1, associated with the marine sponge
, collected in the volcanic CO
vents in Ischia Island (South Italy). Peptide production was triggered at low temperature following the one strain many compounds (OSMAC) method. Both peptides were detected together with other peptides (
-
) via an integrated, untargeted MS/MS-based molecular networking and cheminformatic approach. The planar structure of the peptides was determined by extensive 1D and 2D NMR and HR-MS analysis, and the stereochemistry of the aminoacyl residues was inferred by Marfey's analysis. Peptides
-
are likely to arise from
V1 tailor-made proteolysis of tryptone. Peptides
and
were shown to display antioxidant properties in the ferric-reducing antioxidant power (FRAP) assay.